浓香大豆油的开发及其氧化稳定性的研究

建立一种新型浓香大豆油(ASO)的生产方法。采用超临界萃取技术对焙烤后的大豆进行提取。通过感官评定对大豆焙烤工艺进行评估：在温度170℃条件下烘烤30min 时，焙烤出的大豆具有浓郁的香味。ASO 的萃取率随着大豆粉粒度的增加而提高，大豆粉的粒度为40～60 目时最佳。采用正交试验设计法对ASO 的萃取参数进行研究：萃取率随着温度的升高，先增大后减小，最佳萃取温度为50℃；萃取率随着压力的增大，先增大后减小，最佳萃取压力为25MPa；萃取率随着时间延长逐渐趋于最大值，确定萃取时间为2.5h。通过对氧化诱导期(IP 值)和抗氧化保护系数(Pf 值)的分析，探讨ASO 的氧化稳定性：ASO 和市售大豆油的IP 值分别为8.93、9.47，其他植物油均大于16；向ASO 中添加0.04% 的BHT、PG 分别能使其IP 值从8.93 提高到12.08、18.55，Pf 值分别达到1.353 和2.077，PG 对ASO 的抗氧化效果要明显优于BHT；在ASO 中单独添加0.01% 柠檬酸能使其Pf 值达到2.25，显示较强的抗氧化能力，复合添加0.01% 柠檬酸和0.04% PG 使其Pf 值达到4.14，显示很强的抗氧化能力。

Production and Oxidative Stability of Aromatic Soybean Oil

Roasting followed by supercritical fluid CO2 extraction (SFE) was used to produce aromatic soybean oil (ASO). According to the overall odor evaluation, the optimal temperature and time for roasted soybeans with aromatic flavor were 170 ℃ and 30 min, respectively. With increasing particle size of roasted soybean powder, ASO yield increased and the optimal particle size range was 40 － 60 mesh. Orthogonal array design experiments showed that ASO yield first increased and then decreased with increasing extraction temperature and the optimal extraction temperature was 50 ℃; extraction pressure exhibited the same effect on ASO yield as extraction temperature and its optimal value was 25 MPa; ASO yield progressively ascended to the climax appearing at 2.5 h with increasing extraction time. Induction period (IP) and protection factor (PF) were used to evaluate the oxidative stability of ASO. The IP values of ASO and a commercial brand of soybean oil were determined to be 8.93 and 9.47, respectively, which were lower than those of other plant oils determined to be more than 16. The respective additions of BHT and PG at 0.04% level to ASO resulted in an increase of IP value from 8.93 to 12.08 and 18.55 and an increase of PF to 1.353 and 2.077, respectively, thereby indicating much better antioxidant effect of PG on ASO than BHT. ASO added with 0.01% of citric acid exhibited a PF value of up to 2.25, and thus citric acid was a stronger antioxidant for ASO than PG. A PF value of up to 4.14 was observed when 0.01% of citric acid and 0.04% of PG were added to ASO together.